methods and files provided by the LP solver interface of SCIP
SCIP uses external tools to solve LP relaxations. The communication is realized through an LP interface.
This page lists public interface methods that every LP interface provides. Find the concrete implementation for your LP solver under "src/lpi/".
This file specifies a generic LP solver interface used by SCIP to create, modify, and solve linear programs of the form
min/max obj * x lhs <= A * x <= rhs lb <= x <= ub
and query information about the solution. Although it includes a few SCIP header files, e.g., because it uses SCIP's return codes, it can be used independently of any SCIP instance.
The basis status for (column) variables are as follows:
The basis status for (row) slack variables are:
If the solvers use their status differently, those status codes have to be corrected.
In the methods accessing information about the (inverse of the) basis matrix, the interface assumes the following column-oriented format: slack variables of rows have coefficient +1 and the basis matrix is a regular m times m submatrix of (A,I), where m is the number of rows and I is the identity matrix. This means that if, internally, the LP solver uses coefficients -1 for some of the slack variables, then every row associated with a slack variable whose coefficient is -1 should be negated in order to return the result in terms of the LP interface definition.
The creation of a new LP should always be done in the following ways: Either one can use SCIPlpiLoadColLP() or one first adds empty columns or rows. Then the matrix entries can be added by adding columns and rows, respectively. Adding matrix entries for a row or column that have not been added before will result in an error.
The handling of the objective limit is as follows, if supported by the LP-solver: If the objective is larger than the objective limit for minimization problems or smaller than the objective limit for maximization problems, the solution process can be stopped. This naturally occurs in a branch-and-bound process, where the objective limit is set to the value of the best solution found so far. If the problem is a minimization problem and we use the dual simplex, the dual feasible solutions are maximized. If their value are larger than the objective limit, the process can be stopped. In this case, no feasible integer solution can be found in the corresponding branch.
Some LP-solvers also support the opposite setting, but this can easily be checked after the solution process (i.e., for a minimization problem a check whether the optimal value is smaller than the limit). Note that this check can only be determined at the end of the optimization. Thus, we do not support this.
Files | |
file | lpi.h |
interface methods for specific LP solvers | |
Miscellaneous Methods | |
const char * | SCIPlpiGetSolverName (void) |
const char * | SCIPlpiGetSolverDesc (void) |
void * | SCIPlpiGetSolverPointer (SCIP_LPI *lpi) |
SCIP_RETCODE | SCIPlpiSetIntegralityInformation (SCIP_LPI *lpi, int ncols, int *intInfo) |
LPI Creation and Destruction Methods | |
SCIP_RETCODE | SCIPlpiCreate (SCIP_LPI **lpi, SCIP_MESSAGEHDLR *messagehdlr, const char *name, SCIP_OBJSEN objsen) |
SCIP_RETCODE | SCIPlpiFree (SCIP_LPI **lpi) |
Modification Methods | |
SCIP_RETCODE | SCIPlpiLoadColLP (SCIP_LPI *lpi, SCIP_OBJSEN objsen, int ncols, const SCIP_Real *obj, const SCIP_Real *lb, const SCIP_Real *ub, char **colnames, int nrows, const SCIP_Real *lhs, const SCIP_Real *rhs, char **rownames, int nnonz, const int *beg, const int *ind, const SCIP_Real *val) |
SCIP_RETCODE | SCIPlpiAddCols (SCIP_LPI *lpi, int ncols, const SCIP_Real *obj, const SCIP_Real *lb, const SCIP_Real *ub, char **colnames, int nnonz, const int *beg, const int *ind, const SCIP_Real *val) |
SCIP_RETCODE | SCIPlpiDelCols (SCIP_LPI *lpi, int firstcol, int lastcol) |
SCIP_RETCODE | SCIPlpiDelColset (SCIP_LPI *lpi, int *dstat) |
SCIP_RETCODE | SCIPlpiAddRows (SCIP_LPI *lpi, int nrows, const SCIP_Real *lhs, const SCIP_Real *rhs, char **rownames, int nnonz, const int *beg, const int *ind, const SCIP_Real *val) |
SCIP_RETCODE | SCIPlpiDelRows (SCIP_LPI *lpi, int firstrow, int lastrow) |
SCIP_RETCODE | SCIPlpiDelRowset (SCIP_LPI *lpi, int *dstat) |
SCIP_RETCODE | SCIPlpiClear (SCIP_LPI *lpi) |
SCIP_RETCODE | SCIPlpiChgBounds (SCIP_LPI *lpi, int ncols, const int *ind, const SCIP_Real *lb, const SCIP_Real *ub) |
SCIP_RETCODE | SCIPlpiChgSides (SCIP_LPI *lpi, int nrows, const int *ind, const SCIP_Real *lhs, const SCIP_Real *rhs) |
SCIP_RETCODE | SCIPlpiChgCoef (SCIP_LPI *lpi, int row, int col, SCIP_Real newval) |
SCIP_RETCODE | SCIPlpiChgObjsen (SCIP_LPI *lpi, SCIP_OBJSEN objsen) |
SCIP_RETCODE | SCIPlpiChgObj (SCIP_LPI *lpi, int ncols, const int *ind, const SCIP_Real *obj) |
SCIP_RETCODE | SCIPlpiScaleRow (SCIP_LPI *lpi, int row, SCIP_Real scaleval) |
SCIP_RETCODE | SCIPlpiScaleCol (SCIP_LPI *lpi, int col, SCIP_Real scaleval) |
Data Accessing Methods | |
SCIP_RETCODE | SCIPlpiGetNRows (SCIP_LPI *lpi, int *nrows) |
SCIP_RETCODE | SCIPlpiGetNCols (SCIP_LPI *lpi, int *ncols) |
SCIP_RETCODE | SCIPlpiGetObjsen (SCIP_LPI *lpi, SCIP_OBJSEN *objsen) |
SCIP_RETCODE | SCIPlpiGetNNonz (SCIP_LPI *lpi, int *nnonz) |
SCIP_RETCODE | SCIPlpiGetCols (SCIP_LPI *lpi, int firstcol, int lastcol, SCIP_Real *lb, SCIP_Real *ub, int *nnonz, int *beg, int *ind, SCIP_Real *val) |
SCIP_RETCODE | SCIPlpiGetRows (SCIP_LPI *lpi, int firstrow, int lastrow, SCIP_Real *lhs, SCIP_Real *rhs, int *nnonz, int *beg, int *ind, SCIP_Real *val) |
SCIP_RETCODE | SCIPlpiGetColNames (SCIP_LPI *lpi, int firstcol, int lastcol, char **colnames, char *namestorage, int namestoragesize, int *storageleft) |
SCIP_RETCODE | SCIPlpiGetRowNames (SCIP_LPI *lpi, int firstrow, int lastrow, char **rownames, char *namestorage, int namestoragesize, int *storageleft) |
SCIP_RETCODE | SCIPlpiGetObj (SCIP_LPI *lpi, int firstcol, int lastcol, SCIP_Real *vals) |
SCIP_RETCODE | SCIPlpiGetBounds (SCIP_LPI *lpi, int firstcol, int lastcol, SCIP_Real *lbs, SCIP_Real *ubs) |
SCIP_RETCODE | SCIPlpiGetSides (SCIP_LPI *lpi, int firstrow, int lastrow, SCIP_Real *lhss, SCIP_Real *rhss) |
SCIP_RETCODE | SCIPlpiGetCoef (SCIP_LPI *lpi, int row, int col, SCIP_Real *val) |
LP Basis Methods | |
SCIP_RETCODE | SCIPlpiGetBase (SCIP_LPI *lpi, int *cstat, int *rstat) |
SCIP_RETCODE | SCIPlpiSetBase (SCIP_LPI *lpi, const int *cstat, const int *rstat) |
SCIP_RETCODE | SCIPlpiGetBasisInd (SCIP_LPI *lpi, int *bind) |
SCIP_RETCODE | SCIPlpiGetBInvRow (SCIP_LPI *lpi, int r, SCIP_Real *coef, int *inds, int *ninds) |
SCIP_RETCODE | SCIPlpiGetBInvCol (SCIP_LPI *lpi, int c, SCIP_Real *coef, int *inds, int *ninds) |
SCIP_RETCODE | SCIPlpiGetBInvARow (SCIP_LPI *lpi, int r, const SCIP_Real *binvrow, SCIP_Real *coef, int *inds, int *ninds) |
SCIP_RETCODE | SCIPlpiGetBInvACol (SCIP_LPI *lpi, int c, SCIP_Real *coef, int *inds, int *ninds) |
LPi State Methods | |
SCIP_RETCODE | SCIPlpiGetState (SCIP_LPI *lpi, BMS_BLKMEM *blkmem, SCIP_LPISTATE **lpistate) |
SCIP_RETCODE | SCIPlpiSetState (SCIP_LPI *lpi, BMS_BLKMEM *blkmem, const SCIP_LPISTATE *lpistate) |
SCIP_RETCODE | SCIPlpiClearState (SCIP_LPI *lpi) |
SCIP_RETCODE | SCIPlpiFreeState (SCIP_LPI *lpi, BMS_BLKMEM *blkmem, SCIP_LPISTATE **lpistate) |
SCIP_Bool | SCIPlpiHasStateBasis (SCIP_LPI *lpi, SCIP_LPISTATE *lpistate) |
SCIP_RETCODE | SCIPlpiReadState (SCIP_LPI *lpi, const char *fname) |
SCIP_RETCODE | SCIPlpiWriteState (SCIP_LPI *lpi, const char *fname) |
LPi Pricing Norms Methods | |
SCIP_RETCODE | SCIPlpiGetNorms (SCIP_LPI *lpi, BMS_BLKMEM *blkmem, SCIP_LPINORMS **lpinorms) |
SCIP_RETCODE | SCIPlpiSetNorms (SCIP_LPI *lpi, BMS_BLKMEM *blkmem, const SCIP_LPINORMS *lpinorms) |
SCIP_RETCODE | SCIPlpiFreeNorms (SCIP_LPI *lpi, BMS_BLKMEM *blkmem, SCIP_LPINORMS **lpinorms) |
Parameter Methods | |
SCIP_RETCODE | SCIPlpiGetIntpar (SCIP_LPI *lpi, SCIP_LPPARAM type, int *ival) |
SCIP_RETCODE | SCIPlpiSetIntpar (SCIP_LPI *lpi, SCIP_LPPARAM type, int ival) |
SCIP_RETCODE | SCIPlpiGetRealpar (SCIP_LPI *lpi, SCIP_LPPARAM type, SCIP_Real *dval) |
SCIP_RETCODE | SCIPlpiSetRealpar (SCIP_LPI *lpi, SCIP_LPPARAM type, SCIP_Real dval) |
Numerical Methods | |
SCIP_Real | SCIPlpiInfinity (SCIP_LPI *lpi) |
SCIP_Bool | SCIPlpiIsInfinity (SCIP_LPI *lpi, SCIP_Real val) |
File Interface Methods | |
SCIP_RETCODE | SCIPlpiReadLP (SCIP_LPI *lpi, const char *fname) |
SCIP_RETCODE | SCIPlpiWriteLP (SCIP_LPI *lpi, const char *fname) |
const char* SCIPlpiGetSolverName | ( | void | ) |
gets name and version of LP solver
Referenced by doScipCreate(), lpFlushChgCols(), lpFlushChgRows(), SCIPlpCreate(), SCIPlpMarkFlushed(), and SCIPprintVersion().
const char* SCIPlpiGetSolverDesc | ( | void | ) |
gets description of LP solver (developer, webpage, ...)
Referenced by doScipCreate().
void* SCIPlpiGetSolverPointer | ( | SCIP_LPI * | lpi | ) |
gets pointer for LP solver - use only with great care
The behavior of this function depends on the solver and its use is therefore only recommended if you really know what you are doing. In general, it returns a pointer to the LP solver object.
lpi | pointer to an LP interface structure |
SCIP_RETCODE SCIPlpiSetIntegralityInformation | ( | SCIP_LPI * | lpi, |
int | ncols, | ||
int * | intInfo | ||
) |
pass integrality information about variables to the solver
lpi | pointer to an LP interface structure |
ncols | length of integrality array |
intInfo | integrality array (0: continuous, 1: integer) |
Referenced by lpCopyIntegrality().
SCIP_RETCODE SCIPlpiCreate | ( | SCIP_LPI ** | lpi, |
SCIP_MESSAGEHDLR * | messagehdlr, | ||
const char * | name, | ||
SCIP_OBJSEN | objsen | ||
) |
creates an LP problem object
lpi | pointer to an LP interface structure |
messagehdlr | message handler to use for printing messages, or NULL |
name | problem name |
objsen | objective sense |
Referenced by addConcaveEstimatorMultivariate(), createLP(), initAlternativeLP(), SCIP_DECL_PARAMCHGD(), SCIPlpComputeRelIntPoint(), and SCIPlpCreate().
SCIP_RETCODE SCIPlpiFree | ( | SCIP_LPI ** | lpi | ) |
deletes an LP problem object
lpi | pointer to an LP interface structure |
Referenced by createLP(), SCIP_DECL_CONSEXITSOL(), SCIP_DECL_PARAMCHGD(), SCIPlpComputeRelIntPoint(), SCIPlpFree(), and sepadataFree().
SCIP_RETCODE SCIPlpiLoadColLP | ( | SCIP_LPI * | lpi, |
SCIP_OBJSEN | objsen, | ||
int | ncols, | ||
const SCIP_Real * | obj, | ||
const SCIP_Real * | lb, | ||
const SCIP_Real * | ub, | ||
char ** | colnames, | ||
int | nrows, | ||
const SCIP_Real * | lhs, | ||
const SCIP_Real * | rhs, | ||
char ** | rownames, | ||
int | nnonz, | ||
const int * | beg, | ||
const int * | ind, | ||
const SCIP_Real * | val | ||
) |
copies LP data with column matrix into LP solver
lpi | LP interface structure |
objsen | objective sense |
ncols | number of columns |
obj | objective function values of columns |
lb | lower bounds of columns |
ub | upper bounds of columns |
colnames | column names, or NULL |
nrows | number of rows |
lhs | left hand sides of rows |
rhs | right hand sides of rows |
rownames | row names, or NULL |
nnonz | number of nonzero elements in the constraint matrix |
beg | start index of each column in ind- and val-array |
ind | row indices of constraint matrix entries |
val | values of constraint matrix entries |
SCIP_RETCODE SCIPlpiAddCols | ( | SCIP_LPI * | lpi, |
int | ncols, | ||
const SCIP_Real * | obj, | ||
const SCIP_Real * | lb, | ||
const SCIP_Real * | ub, | ||
char ** | colnames, | ||
int | nnonz, | ||
const int * | beg, | ||
const int * | ind, | ||
const SCIP_Real * | val | ||
) |
adds columns to the LP
lpi | LP interface structure |
ncols | number of columns to be added |
obj | objective function values of new columns |
lb | lower bounds of new columns |
ub | upper bounds of new columns |
colnames | column names, or NULL |
nnonz | number of nonzero elements to be added to the constraint matrix |
beg | start index of each column in ind- and val-array, or NULL if nnonz == 0 |
ind | row indices of constraint matrix entries, or NULL if nnonz == 0 |
val | values of constraint matrix entries, or NULL if nnonz == 0 |
Referenced by addAltLPColumn(), computeRelIntPoint(), createLP(), lpFlushAddCols(), and SCIP_DECL_PARAMCHGD().
SCIP_RETCODE SCIPlpiDelCols | ( | SCIP_LPI * | lpi, |
int | firstcol, | ||
int | lastcol | ||
) |
deletes all columns in the given range from LP
lpi | LP interface structure |
firstcol | first column to be deleted |
lastcol | last column to be deleted |
Referenced by lpFlushDelCols().
SCIP_RETCODE SCIPlpiDelColset | ( | SCIP_LPI * | lpi, |
int * | dstat | ||
) |
deletes columns from SCIP_LPI; the new position of a column must not be greater that its old position
lpi | LP interface structure |
dstat | deletion status of columns input: 1 if column should be deleted, 0 if not output: new position of column, -1 if column was deleted |
Referenced by lpDelColset().
SCIP_RETCODE SCIPlpiAddRows | ( | SCIP_LPI * | lpi, |
int | nrows, | ||
const SCIP_Real * | lhs, | ||
const SCIP_Real * | rhs, | ||
char ** | rownames, | ||
int | nnonz, | ||
const int * | beg, | ||
const int * | ind, | ||
const SCIP_Real * | val | ||
) |
adds rows to the LP
lpi | LP interface structure |
nrows | number of rows to be added |
lhs | left hand sides of new rows |
rhs | right hand sides of new rows |
rownames | row names, or NULL |
nnonz | number of nonzero elements to be added to the constraint matrix |
beg | start index of each row in ind- and val-array, or NULL if nnonz == 0 |
ind | column indices of constraint matrix entries, or NULL if nnonz == 0 |
val | values of constraint matrix entries, or NULL if nnonz == 0 |
Referenced by addAltLPColumn(), computeRelIntPoint(), createLP(), initAlternativeLP(), lpFlushAddRows(), and SCIP_DECL_PARAMCHGD().
SCIP_RETCODE SCIPlpiDelRows | ( | SCIP_LPI * | lpi, |
int | firstrow, | ||
int | lastrow | ||
) |
deletes all rows in the given range from LP
lpi | LP interface structure |
firstrow | first row to be deleted |
lastrow | last row to be deleted |
Referenced by lpFlushDelRows().
SCIP_RETCODE SCIPlpiDelRowset | ( | SCIP_LPI * | lpi, |
int * | dstat | ||
) |
deletes rows from SCIP_LPI; the new position of a row must not be greater that its old position
lpi | LP interface structure |
dstat | deletion status of rows input: 1 if row should be deleted, 0 if not output: new position of row, -1 if row was deleted |
Referenced by lpDelRowset().
SCIP_RETCODE SCIPlpiClear | ( | SCIP_LPI * | lpi | ) |
clears the whole LP
lpi | LP interface structure |
SCIP_RETCODE SCIPlpiChgBounds | ( | SCIP_LPI * | lpi, |
int | ncols, | ||
const int * | ind, | ||
const SCIP_Real * | lb, | ||
const SCIP_Real * | ub | ||
) |
changes lower and upper bounds of columns
lpi | LP interface structure |
ncols | number of columns to change bounds for |
ind | column indices |
lb | values for the new lower bounds |
ub | values for the new upper bounds |
Referenced by fixAltLPVariable(), fixAltLPVariables(), lpFlushChgCols(), lpLexDualSimplex(), runBoundHeuristic(), SCIPcomputeConvexEnvelopeFacet(), SCIPconflictAnalyzeStrongbranch(), unfixAltLPVariable(), and unfixAltLPVariables().
SCIP_RETCODE SCIPlpiChgSides | ( | SCIP_LPI * | lpi, |
int | nrows, | ||
const int * | ind, | ||
const SCIP_Real * | lhs, | ||
const SCIP_Real * | rhs | ||
) |
changes left and right hand sides of rows
lpi | LP interface structure |
nrows | number of rows to change sides for |
ind | row indices |
lhs | new values for left hand sides |
rhs | new values for right hand sides |
Referenced by lpFlushChgRows(), lpLexDualSimplex(), runBoundHeuristic(), scaleFirstRow(), and SCIPcomputeConvexEnvelopeFacet().
SCIP_RETCODE SCIPlpiChgCoef | ( | SCIP_LPI * | lpi, |
int | row, | ||
int | col, | ||
SCIP_Real | newval | ||
) |
changes a single coefficient
lpi | LP interface structure |
row | row number of coefficient to change |
col | column number of coefficient to change |
newval | new value of coefficient |
Referenced by updateFirstRow(), updateFirstRowGlobal(), and updateObjUpperbound().
SCIP_RETCODE SCIPlpiChgObjsen | ( | SCIP_LPI * | lpi, |
SCIP_OBJSEN | objsen | ||
) |
changes the objective sense
lpi | LP interface structure |
objsen | new objective sense |
SCIP_RETCODE SCIPlpiChgObj | ( | SCIP_LPI * | lpi, |
int | ncols, | ||
const int * | ind, | ||
const SCIP_Real * | obj | ||
) |
changes objective values of columns in the LP
lpi | LP interface structure |
ncols | number of columns to change objective value for |
ind | column indices to change objective value for |
obj | new objective values for columns |
Referenced by lpFlushChgCols(), lpLexDualSimplex(), SCIPcomputeConvexEnvelopeFacet(), setAltLPObj(), and setAltLPObjZero().
SCIP_RETCODE SCIPlpiScaleRow | ( | SCIP_LPI * | lpi, |
int | row, | ||
SCIP_Real | scaleval | ||
) |
multiplies a row with a non-zero scalar; for negative scalars, the row's sense is switched accordingly
lpi | LP interface structure |
row | row number to scale |
scaleval | scaling multiplier |
SCIP_RETCODE SCIPlpiScaleCol | ( | SCIP_LPI * | lpi, |
int | col, | ||
SCIP_Real | scaleval | ||
) |
multiplies a column with a non-zero scalar; the objective value is multiplied with the scalar, and the bounds are divided by the scalar; for negative scalars, the column's bounds are switched
lpi | LP interface structure |
col | column number to scale |
scaleval | scaling multiplier |
SCIP_RETCODE SCIPlpiGetNRows | ( | SCIP_LPI * | lpi, |
int * | nrows | ||
) |
gets the number of rows in the LP
lpi | LP interface structure |
nrows | pointer to store the number of rows |
Referenced by addAltLPColumn(), SCIPcomputeConvexEnvelopeFacet(), and SCIPlpFlush().
SCIP_RETCODE SCIPlpiGetNCols | ( | SCIP_LPI * | lpi, |
int * | ncols | ||
) |
gets the number of columns in the LP
lpi | LP interface structure |
ncols | pointer to store the number of cols |
Referenced by addAltLPColumn(), checkIISlocal(), checkLPBoundsClean(), computeRelIntPoint(), extendToCover(), scaleFirstRow(), SCIPcomputeConvexEnvelopeFacet(), and SCIPlpFlush().
SCIP_RETCODE SCIPlpiGetObjsen | ( | SCIP_LPI * | lpi, |
SCIP_OBJSEN * | objsen | ||
) |
gets the objective sense of the LP
lpi | LP interface structure |
objsen | pointer to store objective sense |
SCIP_RETCODE SCIPlpiGetNNonz | ( | SCIP_LPI * | lpi, |
int * | nnonz | ||
) |
gets the number of nonzero elements in the LP constraint matrix
lpi | LP interface structure |
nnonz | pointer to store the number of nonzeros |
SCIP_RETCODE SCIPlpiGetCols | ( | SCIP_LPI * | lpi, |
int | firstcol, | ||
int | lastcol, | ||
SCIP_Real * | lb, | ||
SCIP_Real * | ub, | ||
int * | nnonz, | ||
int * | beg, | ||
int * | ind, | ||
SCIP_Real * | val | ||
) |
gets columns from LP problem object; the arrays have to be large enough to store all values; Either both, lb and ub, have to be NULL, or both have to be non-NULL, either nnonz, beg, ind, and val have to be NULL, or all of them have to be non-NULL.
lpi | LP interface structure |
firstcol | first column to get from LP |
lastcol | last column to get from LP |
lb | buffer to store the lower bound vector, or NULL |
ub | buffer to store the upper bound vector, or NULL |
nnonz | pointer to store the number of nonzero elements returned, or NULL |
beg | buffer to store start index of each column in ind- and val-array, or NULL |
ind | buffer to store row indices of constraint matrix entries, or NULL |
val | buffer to store values of constraint matrix entries, or NULL |
SCIP_RETCODE SCIPlpiGetRows | ( | SCIP_LPI * | lpi, |
int | firstrow, | ||
int | lastrow, | ||
SCIP_Real * | lhs, | ||
SCIP_Real * | rhs, | ||
int * | nnonz, | ||
int * | beg, | ||
int * | ind, | ||
SCIP_Real * | val | ||
) |
gets rows from LP problem object; the arrays have to be large enough to store all values. Either both, lhs and rhs, have to be NULL, or both have to be non-NULL, either nnonz, beg, ind, and val have to be NULL, or all of them have to be non-NULL.
lpi | LP interface structure |
firstrow | first row to get from LP |
lastrow | last row to get from LP |
lhs | buffer to store left hand side vector, or NULL |
rhs | buffer to store right hand side vector, or NULL |
nnonz | pointer to store the number of nonzero elements returned, or NULL |
beg | buffer to store start index of each row in ind- and val-array, or NULL |
ind | buffer to store column indices of constraint matrix entries, or NULL |
val | buffer to store values of constraint matrix entries, or NULL |
Referenced by scaleFirstRow().
SCIP_RETCODE SCIPlpiGetColNames | ( | SCIP_LPI * | lpi, |
int | firstcol, | ||
int | lastcol, | ||
char ** | colnames, | ||
char * | namestorage, | ||
int | namestoragesize, | ||
int * | storageleft | ||
) |
gets column names
lpi | LP interface structure |
firstcol | first column to get name from LP |
lastcol | last column to get name from LP |
colnames | pointers to column names (of size at least lastcol-firstcol+1) |
namestorage | storage for col names |
namestoragesize | size of namestorage (if 0, -storageleft returns the storage needed) |
storageleft | amount of storage left (if < 0 the namestorage was not big enough) |
SCIP_RETCODE SCIPlpiGetRowNames | ( | SCIP_LPI * | lpi, |
int | firstrow, | ||
int | lastrow, | ||
char ** | rownames, | ||
char * | namestorage, | ||
int | namestoragesize, | ||
int * | storageleft | ||
) |
gets row names
lpi | LP interface structure |
firstrow | first row to get name from LP |
lastrow | last row to get name from LP |
rownames | pointers to row names (of size at least lastrow-firstrow+1) |
namestorage | storage for row names |
namestoragesize | size of namestorage (if 0, -storageleft returns the storage needed) |
storageleft | amount of storage left (if < 0 the namestorage was not big enough) |
SCIP_RETCODE SCIPlpiGetObj | ( | SCIP_LPI * | lpi, |
int | firstcol, | ||
int | lastcol, | ||
SCIP_Real * | vals | ||
) |
gets objective coefficients from LP problem object
lpi | LP interface structure |
firstcol | first column to get objective coefficient for |
lastcol | last column to get objective coefficient for |
vals | array to store objective coefficients |
Referenced by lpFlushChgCols(), lpLexDualSimplex(), and SCIPlpMarkFlushed().
SCIP_RETCODE SCIPlpiGetBounds | ( | SCIP_LPI * | lpi, |
int | firstcol, | ||
int | lastcol, | ||
SCIP_Real * | lbs, | ||
SCIP_Real * | ubs | ||
) |
gets current bounds from LP problem object
lpi | LP interface structure |
firstcol | first column to get bounds for |
lastcol | last column to get bounds for |
lbs | array to store lower bound values, or NULL |
ubs | array to store upper bound values, or NULL |
Referenced by checkLPBoundsClean(), lpFlushChgCols(), lpLexDualSimplex(), and SCIPlpMarkFlushed().
SCIP_RETCODE SCIPlpiGetSides | ( | SCIP_LPI * | lpi, |
int | firstrow, | ||
int | lastrow, | ||
SCIP_Real * | lhss, | ||
SCIP_Real * | rhss | ||
) |
gets current row sides from LP problem object
lpi | LP interface structure |
firstrow | first row to get sides for |
lastrow | last row to get sides for |
lhss | array to store left hand side values, or NULL |
rhss | array to store right hand side values, or NULL |
Referenced by getFarkasProof(), lpFlushChgRows(), lpLexDualSimplex(), and SCIPlpMarkFlushed().
SCIP_RETCODE SCIPlpiGetCoef | ( | SCIP_LPI * | lpi, |
int | row, | ||
int | col, | ||
SCIP_Real * | val | ||
) |
gets a single coefficient
lpi | LP interface structure |
row | row number of coefficient |
col | column number of coefficient |
val | pointer to store the value of the coefficient |
Referenced by SCIPdummyDebugMethodForSun(), and updateObjUpperbound().
SCIP_RETCODE SCIPlpiSolvePrimal | ( | SCIP_LPI * | lpi | ) |
calls primal simplex to solve the LP
lpi | LP interface structure |
Referenced by checkAltLPInfeasible(), lpLexDualSimplex(), lpPrimalSimplex(), SCIP_DECL_PARAMCHGD(), and SCIPcomputeConvexEnvelopeFacet().
SCIP_RETCODE SCIPlpiSolveDual | ( | SCIP_LPI * | lpi | ) |
calls dual simplex to solve the LP
lpi | LP interface structure |
Referenced by checkAltLPInfeasible(), computeRelIntPoint(), conflictAnalyzeLP(), lpDualSimplex(), lpLexDualSimplex(), runBoundHeuristic(), SCIPcomputeConvexEnvelopeFacet(), and SCIPconflictAnalyzeStrongbranch().
SCIP_RETCODE SCIPlpiSolveBarrier | ( | SCIP_LPI * | lpi, |
SCIP_Bool | crossover | ||
) |
calls barrier or interior point algorithm to solve the LP with crossover to simplex basis
lpi | LP interface structure |
crossover | perform crossover |
Referenced by lpBarrier().
SCIP_RETCODE SCIPlpiStartStrongbranch | ( | SCIP_LPI * | lpi | ) |
start strong branching - call before any strong branching
lpi | LP interface structure |
Referenced by SCIPconflictAnalyzeStrongbranch(), and SCIPlpStartStrongbranch().
SCIP_RETCODE SCIPlpiEndStrongbranch | ( | SCIP_LPI * | lpi | ) |
end strong branching - call after any strong branching
lpi | LP interface structure |
Referenced by SCIPconflictAnalyzeStrongbranch(), and SCIPlpEndStrongbranch().
SCIP_RETCODE SCIPlpiStrongbranchFrac | ( | SCIP_LPI * | lpi, |
int | col, | ||
SCIP_Real | psol, | ||
int | itlim, | ||
SCIP_Real * | down, | ||
SCIP_Real * | up, | ||
SCIP_Bool * | downvalid, | ||
SCIP_Bool * | upvalid, | ||
int * | iter | ||
) |
performs strong branching iterations on one fractional candidate
lpi | LP interface structure |
col | column to apply strong branching on |
psol | fractional current primal solution value of column |
itlim | iteration limit for strong branchings |
down | stores dual bound after branching column down |
up | stores dual bound after branching column up |
downvalid | stores whether the returned down value is a valid dual bound; otherwise, it can only be used as an estimate value |
upvalid | stores whether the returned up value is a valid dual bound; otherwise, it can only be used as an estimate value |
iter | stores total number of strong branching iterations, or -1; may be NULL |
Referenced by SCIPcolGetStrongbranch().
SCIP_RETCODE SCIPlpiStrongbranchesFrac | ( | SCIP_LPI * | lpi, |
int * | cols, | ||
int | ncols, | ||
SCIP_Real * | psols, | ||
int | itlim, | ||
SCIP_Real * | down, | ||
SCIP_Real * | up, | ||
SCIP_Bool * | downvalid, | ||
SCIP_Bool * | upvalid, | ||
int * | iter | ||
) |
performs strong branching iterations on given fractional candidates
lpi | LP interface structure |
cols | columns to apply strong branching on |
ncols | number of columns |
psols | fractional current primal solution values of columns |
itlim | iteration limit for strong branchings |
down | stores dual bounds after branching columns down |
up | stores dual bounds after branching columns up |
downvalid | stores whether the returned down values are valid dual bounds; otherwise, they can only be used as an estimate values |
upvalid | stores whether the returned up values are a valid dual bounds; otherwise, they can only be used as an estimate values |
iter | stores total number of strong branching iterations, or -1; may be NULL |
Referenced by SCIPcolGetStrongbranches().
SCIP_RETCODE SCIPlpiStrongbranchInt | ( | SCIP_LPI * | lpi, |
int | col, | ||
SCIP_Real | psol, | ||
int | itlim, | ||
SCIP_Real * | down, | ||
SCIP_Real * | up, | ||
SCIP_Bool * | downvalid, | ||
SCIP_Bool * | upvalid, | ||
int * | iter | ||
) |
performs strong branching iterations on one candidate with integral value
lpi | LP interface structure |
col | column to apply strong branching on |
psol | current integral primal solution value of column |
itlim | iteration limit for strong branchings |
down | stores dual bound after branching column down |
up | stores dual bound after branching column up |
downvalid | stores whether the returned down value is a valid dual bound; otherwise, it can only be used as an estimate value |
upvalid | stores whether the returned up value is a valid dual bound; otherwise, it can only be used as an estimate value |
iter | stores total number of strong branching iterations, or -1; may be NULL |
Referenced by SCIPcolGetStrongbranch().
SCIP_RETCODE SCIPlpiStrongbranchesInt | ( | SCIP_LPI * | lpi, |
int * | cols, | ||
int | ncols, | ||
SCIP_Real * | psols, | ||
int | itlim, | ||
SCIP_Real * | down, | ||
SCIP_Real * | up, | ||
SCIP_Bool * | downvalid, | ||
SCIP_Bool * | upvalid, | ||
int * | iter | ||
) |
performs strong branching iterations on given candidates with integral values
lpi | LP interface structure |
cols | columns to apply strong branching on |
ncols | number of columns |
psols | current integral primal solution values of columns |
itlim | iteration limit for strong branchings |
down | stores dual bounds after branching columns down |
up | stores dual bounds after branching columns up |
downvalid | stores whether the returned down values are valid dual bounds; otherwise, they can only be used as an estimate values |
upvalid | stores whether the returned up values are a valid dual bounds; otherwise, they can only be used as an estimate values |
iter | stores total number of strong branching iterations, or -1; may be NULL |
Referenced by SCIPcolGetStrongbranches().
returns whether a solve method was called after the last modification of the LP
lpi | LP interface structure |
Referenced by performStrongbranchWithPropagation(), and SCIPconflictAnalyzeLP().
SCIP_RETCODE SCIPlpiGetSolFeasibility | ( | SCIP_LPI * | lpi, |
SCIP_Bool * | primalfeasible, | ||
SCIP_Bool * | dualfeasible | ||
) |
gets information about primal and dual feasibility of the current LP solution
lpi | LP interface structure |
primalfeasible | stores primal feasibility status |
dualfeasible | stores dual feasibility status |
Referenced by lpAlgorithm().
returns TRUE iff LP is proven to have a primal unbounded ray (but not necessary a primal feasible point); this does not necessarily mean, that the solver knows and can return the primal ray
lpi | LP interface structure |
Referenced by checkAltLPInfeasible(), and lpSolve().
returns TRUE iff LP is proven to have a primal unbounded ray (but not necessary a primal feasible point), and the solver knows and can return the primal ray
lpi | LP interface structure |
Referenced by lpSolve(), SCIPlpGetPrimalRay(), and SCIPlpGetUnboundedSol().
returns TRUE iff LP is proven to be primal unbounded
lpi | LP interface structure |
Referenced by checkAltLPInfeasible().
returns TRUE iff LP is proven to be primal infeasible
lpi | LP interface structure |
Referenced by checkAltLPInfeasible(), conflictAnalyzeLP(), getFarkasProof(), lpSolve(), runBoundHeuristic(), SCIP_DECL_PARAMCHGD(), and SCIPconflictAnalyzeLP().
returns TRUE iff LP is proven to be primal feasible
lpi | LP interface structure |
Referenced by lpSolve().
returns TRUE iff LP is proven to have a dual unbounded ray (but not necessary a dual feasible point); this does not necessarily mean, that the solver knows and can return the dual ray
lpi | LP interface structure |
returns TRUE iff LP is proven to have a dual unbounded ray (but not necessary a dual feasible point), and the solver knows and can return the dual ray
lpi | LP interface structure |
Referenced by getFarkasProof(), lpSolve(), and SCIPlpSolveAndEval().
returns TRUE iff LP is proven to be dual unbounded
lpi | LP interface structure |
returns TRUE iff LP is proven to be dual infeasible
lpi | LP interface structure |
returns TRUE iff LP is proven to be dual feasible
lpi | LP interface structure |
Referenced by conflictAnalyzeLP(), getFarkasProof(), lpSolve(), performStrongbranchWithPropagation(), and runBoundHeuristic().
returns TRUE iff LP was solved to optimality
lpi | LP interface structure |
Referenced by checkAltLPInfeasible(), computeRelIntPoint(), conflictAnalyzeLP(), lpLexDualSimplex(), and lpSolve().
returns TRUE iff current LP basis is stable
lpi | LP interface structure |
Referenced by checkAltLPInfeasible(), and lpSolveStable().
returns TRUE iff the objective limit was reached
lpi | LP interface structure |
Referenced by conflictAnalyzeLP(), getFarkasProof(), lpSolve(), runBoundHeuristic(), and SCIPlpSolveAndEval().
returns TRUE iff the iteration limit was reached
lpi | LP interface structure |
Referenced by computeRelIntPoint(), lpSolve(), and lpSolveStable().
returns TRUE iff the time limit was reached
lpi | LP interface structure |
Referenced by computeRelIntPoint(), and lpSolve().
int SCIPlpiGetInternalStatus | ( | SCIP_LPI * | lpi | ) |
returns the internal solution status of the solver
lpi | LP interface structure |
Referenced by checkAltLPInfeasible(), and lpSolve().
SCIP_RETCODE SCIPlpiIgnoreInstability | ( | SCIP_LPI * | lpi, |
SCIP_Bool * | success | ||
) |
tries to reset the internal status of the LP solver in order to ignore an instability of the last solving call
lpi | LP interface structure |
success | pointer to store, whether the instability could be ignored |
Referenced by lpSolveStable().
SCIP_RETCODE SCIPlpiGetObjval | ( | SCIP_LPI * | lpi, |
SCIP_Real * | objval | ||
) |
gets objective value of solution
lpi | LP interface structure |
objval | stores the objective value |
Referenced by conflictAnalyzeLP(), getDualProof(), lpSolve(), performStrongbranchWithPropagation(), runBoundHeuristic(), and SCIPlpSolveAndEval().
SCIP_RETCODE SCIPlpiGetSol | ( | SCIP_LPI * | lpi, |
SCIP_Real * | objval, | ||
SCIP_Real * | primsol, | ||
SCIP_Real * | dualsol, | ||
SCIP_Real * | activity, | ||
SCIP_Real * | redcost | ||
) |
gets primal and dual solution vectors for feasible LPs
lpi | LP interface structure |
objval | stores the objective value, may be NULL if not needed |
primsol | primal solution vector, may be NULL if not needed |
dualsol | dual solution vector, may be NULL if not needed |
activity | row activity vector, may be NULL if not needed |
redcost | reduced cost vector, may be NULL if not needed |
Referenced by computeRelIntPoint(), extendToCover(), getDualProof(), lpLexDualSimplex(), SCIPcomputeConvexEnvelopeFacet(), SCIPlpGetSol(), and SCIPlpGetUnboundedSol().
SCIP_RETCODE SCIPlpiGetPrimalRay | ( | SCIP_LPI * | lpi, |
SCIP_Real * | ray | ||
) |
gets primal ray for unbounded LPs
lpi | LP interface structure |
ray | primal ray |
Referenced by SCIPlpGetPrimalRay(), and SCIPlpGetUnboundedSol().
SCIP_RETCODE SCIPlpiGetDualfarkas | ( | SCIP_LPI * | lpi, |
SCIP_Real * | dualfarkas | ||
) |
gets dual Farkas proof for infeasibility
lpi | LP interface structure |
dualfarkas | dual Farkas row multipliers |
Referenced by getFarkasProof(), and SCIPlpGetDualfarkas().
SCIP_RETCODE SCIPlpiGetIterations | ( | SCIP_LPI * | lpi, |
int * | iterations | ||
) |
gets the number of LP iterations of the last solve call
lpi | LP interface structure |
iterations | pointer to store the number of iterations of the last solve call |
Referenced by conflictAnalyzeLP(), runBoundHeuristic(), SCIPconflictAnalyzeStrongbranch(), and SCIPlpGetIterations().
SCIP_RETCODE SCIPlpiGetRealSolQuality | ( | SCIP_LPI * | lpi, |
SCIP_LPSOLQUALITY | qualityindicator, | ||
SCIP_Real * | quality | ||
) |
gets information about the quality of an LP solution
Such information is usually only available, if also a (maybe not optimal) solution is available. The LPI should return SCIP_INVALID for quality
, if the requested quantity is not available.
lpi | LP interface structure |
qualityindicator | indicates which quality should be returned |
quality | pointer to store quality number |
Referenced by checkAltLPInfeasible(), SCIP_DECL_DISPOUTPUT(), and SCIPprintLPSolutionQuality().
SCIP_RETCODE SCIPlpiGetBase | ( | SCIP_LPI * | lpi, |
int * | cstat, | ||
int * | rstat | ||
) |
gets current basis status for columns and rows; arrays must be large enough to store the basis status
lpi | LP interface structure |
cstat | array to store column basis status, or NULL |
rstat | array to store row basis status, or NULL |
Referenced by lpLexDualSimplex(), SCIPconflictAnalyzeStrongbranch(), SCIPlpGetBase(), and SCIPlpGetSol().
SCIP_RETCODE SCIPlpiSetBase | ( | SCIP_LPI * | lpi, |
const int * | cstat, | ||
const int * | rstat | ||
) |
sets current basis status for columns and rows
lpi | LP interface structure |
cstat | array with column basis status |
rstat | array with row basis status |
Referenced by SCIPconflictAnalyzeStrongbranch().
SCIP_RETCODE SCIPlpiGetBasisInd | ( | SCIP_LPI * | lpi, |
int * | bind | ||
) |
returns the indices of the basic columns and rows; basic column n gives value n, basic row m gives value -1-m
lpi | LP interface structure |
bind | pointer to store basis indices ready to keep number of rows entries |
Referenced by SCIPlpGetBasisInd().
SCIP_RETCODE SCIPlpiGetBInvRow | ( | SCIP_LPI * | lpi, |
int | r, | ||
SCIP_Real * | coef, | ||
int * | inds, | ||
int * | ninds | ||
) |
get row of inverse basis matrix B^-1
lpi | LP interface structure |
r | row number |
coef | pointer to store the coefficients of the row |
inds | array to store the non-zero indices, or NULL |
ninds | pointer to store the number of non-zero indices, or NULL (-1: if we do not store sparsity informations) |
Referenced by SCIPlpGetBInvRow().
SCIP_RETCODE SCIPlpiGetBInvCol | ( | SCIP_LPI * | lpi, |
int | c, | ||
SCIP_Real * | coef, | ||
int * | inds, | ||
int * | ninds | ||
) |
get column of inverse basis matrix B^-1
lpi | LP interface structure |
c | column number of B^-1; this is NOT the number of the column in the LP; you have to call SCIPlpiGetBasisInd() to get the array which links the B^-1 column numbers to the row and column numbers of the LP! c must be between 0 and nrows-1, since the basis has the size nrows * nrows |
coef | pointer to store the coefficients of the column |
inds | array to store the non-zero indices, or NULL |
ninds | pointer to store the number of non-zero indices, or NULL (-1: if we do not store sparsity informations) |
Referenced by SCIPlpGetBInvCol().
SCIP_RETCODE SCIPlpiGetBInvARow | ( | SCIP_LPI * | lpi, |
int | r, | ||
const SCIP_Real * | binvrow, | ||
SCIP_Real * | coef, | ||
int * | inds, | ||
int * | ninds | ||
) |
get row of inverse basis matrix times constraint matrix B^-1 * A
lpi | LP interface structure |
r | row number |
binvrow | row in (A_B)^-1 from prior call to SCIPlpiGetBInvRow(), or NULL |
coef | vector to return coefficients |
inds | array to store the non-zero indices, or NULL |
ninds | pointer to store the number of non-zero indices, or NULL (-1: if we do not store sparsity informations) |
Referenced by SCIPlpGetBInvARow().
SCIP_RETCODE SCIPlpiGetBInvACol | ( | SCIP_LPI * | lpi, |
int | c, | ||
SCIP_Real * | coef, | ||
int * | inds, | ||
int * | ninds | ||
) |
get column of inverse basis matrix times constraint matrix B^-1 * A
lpi | LP interface structure |
c | column number |
coef | vector to return coefficients |
inds | array to store the non-zero indices, or NULL |
ninds | pointer to store the number of non-zero indices, or NULL (-1: if we do not store sparsity informations) |
Referenced by SCIPlpGetBInvACol().
SCIP_RETCODE SCIPlpiGetState | ( | SCIP_LPI * | lpi, |
BMS_BLKMEM * | blkmem, | ||
SCIP_LPISTATE ** | lpistate | ||
) |
stores LPi state (like basis information) into lpistate object
lpi | LP interface structure |
blkmem | block memory |
lpistate | pointer to LPi state information (like basis information) |
Referenced by SCIPlpGetState(), and SCIPlpStartDive().
SCIP_RETCODE SCIPlpiSetState | ( | SCIP_LPI * | lpi, |
BMS_BLKMEM * | blkmem, | ||
const SCIP_LPISTATE * | lpistate | ||
) |
loads LPi state (like basis information) into solver; note that the LP might have been extended with additional columns and rows since the state was stored with SCIPlpiGetState()
lpi | LP interface structure |
blkmem | block memory |
lpistate | LPi state information (like basis information) |
Referenced by SCIPlpSetState().
SCIP_RETCODE SCIPlpiClearState | ( | SCIP_LPI * | lpi | ) |
clears current LPi state (like basis information) of the solver
lpi | LP interface structure |
Referenced by SCIPtreeEndProbing().
SCIP_RETCODE SCIPlpiFreeState | ( | SCIP_LPI * | lpi, |
BMS_BLKMEM * | blkmem, | ||
SCIP_LPISTATE ** | lpistate | ||
) |
frees LPi state information
lpi | LP interface structure |
blkmem | block memory |
lpistate | pointer to LPi state information (like basis information) |
Referenced by SCIPlpFreeState().
SCIP_Bool SCIPlpiHasStateBasis | ( | SCIP_LPI * | lpi, |
SCIP_LPISTATE * | lpistate | ||
) |
checks, whether the given LPi state contains simplex basis information
lpi | LP interface structure |
lpistate | LPi state information (like basis information) |
Referenced by SCIPlpSetState().
SCIP_RETCODE SCIPlpiReadState | ( | SCIP_LPI * | lpi, |
const char * | fname | ||
) |
reads LPi state (like basis information from a file
lpi | LP interface structure |
fname | file name |
SCIP_RETCODE SCIPlpiWriteState | ( | SCIP_LPI * | lpi, |
const char * | fname | ||
) |
writes LPi state (like basis information) to a file
lpi | LP interface structure |
fname | file name |
SCIP_RETCODE SCIPlpiGetNorms | ( | SCIP_LPI * | lpi, |
BMS_BLKMEM * | blkmem, | ||
SCIP_LPINORMS ** | lpinorms | ||
) |
stores LPi pricing norms into lpinorms object
lpi | LP interface structure |
blkmem | block memory |
lpinorms | pointer to LPi pricing norms information |
Referenced by SCIPlpGetNorms().
SCIP_RETCODE SCIPlpiSetNorms | ( | SCIP_LPI * | lpi, |
BMS_BLKMEM * | blkmem, | ||
const SCIP_LPINORMS * | lpinorms | ||
) |
loads LPi pricing norms into solver; note that the LP might have been extended with additional columns and rows since the norms were stored with SCIPlpiGetNorms()
lpi | LP interface structure |
blkmem | block memory |
lpinorms | LPi pricing norms information |
Referenced by SCIPlpSetNorms().
SCIP_RETCODE SCIPlpiFreeNorms | ( | SCIP_LPI * | lpi, |
BMS_BLKMEM * | blkmem, | ||
SCIP_LPINORMS ** | lpinorms | ||
) |
frees LPi pricing norms information
lpi | LP interface structure |
blkmem | block memory |
lpinorms | pointer to LPi pricing norms information |
Referenced by SCIPlpFreeNorms().
SCIP_RETCODE SCIPlpiGetIntpar | ( | SCIP_LPI * | lpi, |
SCIP_LPPARAM | type, | ||
int * | ival | ||
) |
gets integer parameter of LP
lpi | LP interface structure |
type | parameter number |
ival | buffer to store the parameter value |
Referenced by lpCheckIntpar(), and SCIPlpStartDive().
SCIP_RETCODE SCIPlpiSetIntpar | ( | SCIP_LPI * | lpi, |
SCIP_LPPARAM | type, | ||
int | ival | ||
) |
sets integer parameter of LP
lpi | LP interface structure |
type | parameter number |
ival | parameter value |
Referenced by checkAltLPInfeasible(), computeRelIntPoint(), conflictAnalyzeLP(), extendToCover(), initAlternativeLP(), lpSetIntpar(), runBoundHeuristic(), and SCIP_DECL_CONSCHECK().
SCIP_RETCODE SCIPlpiGetRealpar | ( | SCIP_LPI * | lpi, |
SCIP_LPPARAM | type, | ||
SCIP_Real * | dval | ||
) |
gets floating point parameter of LP
lpi | LP interface structure |
type | parameter number |
dval | buffer to store the parameter value |
Referenced by conflictAnalyzeLP(), and lpCheckRealpar().
SCIP_RETCODE SCIPlpiSetRealpar | ( | SCIP_LPI * | lpi, |
SCIP_LPPARAM | type, | ||
SCIP_Real | dval | ||
) |
sets floating point parameter of LP
lpi | LP interface structure |
type | parameter number |
dval | parameter value |
Referenced by computeRelIntPoint(), conflictAnalyzeLP(), lpSetRealpar(), and runBoundHeuristic().
returns value treated as infinity in the LP solver
lpi | LP interface structure |
Referenced by addAltLPColumn(), addBdchg(), computeRelIntPoint(), conflictAnalyzeLP(), lpAlgorithm(), lpFlushAddCols(), lpFlushAddRows(), lpFlushChgCols(), lpFlushChgRows(), lpSetObjlim(), runBoundHeuristic(), SCIP_DECL_PARAMCHGD(), SCIPlpCreate(), SCIPlpMarkFlushed(), SCIPlpSolveAndEval(), solveNodeLP(), unfixAltLPVariable(), unfixAltLPVariables(), and updateLazyBounds().
checks if given value is treated as infinity in the LP solver
lpi | LP interface structure |
val | value to be checked for infinity |
Referenced by addBdchg(), checkLPBoundsClean(), and performStrongbranchWithPropagation().
SCIP_RETCODE SCIPlpiReadLP | ( | SCIP_LPI * | lpi, |
const char * | fname | ||
) |
reads LP from a file
lpi | LP interface structure |
fname | file name |
SCIP_RETCODE SCIPlpiWriteLP | ( | SCIP_LPI * | lpi, |
const char * | fname | ||
) |
writes LP to a file
lpi | LP interface structure |
fname | file name |
Referenced by addAltLPColumn(), computeRelIntPoint(), SCIP_DECL_PARAMCHGD(), SCIPlpWrite(), and updateObjUpperbound().